Final answer:
Sodium (Na) has the largest atomic radius among the given atoms due to its position in the periodic table, being in the same group as Lithium but in a lower period and belonging to a group that generally has larger radii compared to the halogens.
Step-by-step explanation:
Of the listed atoms, Na (Sodium) has the largest atomic radius. When comparing atomic radii within the periodic table, we must consider two main trends: from top to bottom within a group, the atomic radius increases because additional electron shells are added, and from left to right across a period, the atomic radius decreases due to the increasing nuclear charge pulling electrons closer to the nucleus.
In the case of Li (Lithium), Na (Sodium), F (Fluorine), and Cl (Chlorine), Lithium and Sodium are both in Group 1 (alkali metals), while Fluorine and Chlorine are in Group 17 (halogens). Sodium appears below Lithium in the same group, indicating a larger radius as it has an additional electron shell. Comparing Na to the halogens (F and Cl), despite being further right on the period, Group 1 elements still have a larger radius than Group 17 elements due to less effective nuclear charge.
Therefore, Sodium will have a larger atomic radius than Lithium and significantly larger compared to the smaller radii of Fluorine and Chlorine.